# gabrelov

Senior Members

52

1. ## how does something become a law in science?

I would give another example that sometimes calculation cannot substitute to reality. It was during the time when aicraft was trying to go past speed of sound. Calculations showed that if an object tries to go beyond Mach 1, the drag will increase to almost infinity, thus requiring infinite thrust. So by then most of them agree no one can go faster than speed of sound. But an experiment using an aicraft doing a dive going mach 1 broke this theory, man can travel faster than speed of sound. They have to revise the calculations back then. So for humans we try to understand something and thus we create theories maybe not just from observation but calculation but in reality we may have overlook some aspects of it that may totally change what we know so far. Anyways actually we only call it laws of nature, this is a genral term for something, it is not name for some kind of formula or a single of observation. So we call it laws of nature because we cannot change it base on what we observe, it holds its own meaning for itself or we cannot define it.
2. ## How to organize student work

How about make the lab work exciting, like tell them what could be the result of their work. As a student before we do the same not attending lab works specially if the activity is boring or repeated. Are they doing it group work? If so why not give the group we the best work a credit, grades or exceptions may do.
3. ## Is there a quick way to determine if this is a prime number?

Thanks very much
4. ## how does something become a law in science?

Yes an apple will fall before even humans existed. It was not invented by humans but is limited to what we understand. Eg: law of gravity of newton and einstein. What they understand before is that due to mass that objects fall, even before gravity was discovered. The later comes law of gravity with objects of proportional mass and then came the curvature of fabric of space time. We did not invent this laws, this is the result of what we observed so far. If still people and scientist are not satisfied then it ends up as theory, but we may brand it as thoery but in reality its a law or vice versa, we brand it as a law but in reality its not. If you are questioning how this laws existed, as I mentioned above AFAIk we cannot say at atmost 100% that all laws are really laws, we have to remember we have macroscopic and quantum level. Laws may not apply to the other. I would not want to guess how they existed for the first place, but rather we have to dig deep into the level of how everything begun, the constituents of this universe which in turn limits what we understand so far. There are still things we don't see remember, dark energy, dark matter, maybe they have effect on gravity. This is what I want to express. What I wanna say: Don't limit yourself to what the laws says, sometimes they maybe exceptions and that is what science is all about. Anyways that is why I love science, there is more out there than meets the eye. We have lot more to learn and that is why it is not boring, everyday we progress we learn and we discover new things, we also create history.
5. ## how does something become a law in science?

Laws exist even before we all exist. But remember if there are multiverse we cannot say law here applies there. Much like country with different law. But the law is only limited to what we understand so far. Eg; Newton law and einstein law of gravity.
6. ## Is it an undisputed fact that machines can never be 100% efficient?

Law of thermodynamics says? there is definitely soething tansformed to heat energy. You apply force to a simple machine? you already burn energy and some tranformed to heat so there are still loses. But if we compute only during which the force is applied there are still loses. Eg: law of gravitation that each object aith mass pulls one another adds to something you need to overcome and will need you additional force. The scale might be mocroscopic but still loses ssuming .0001%
7. ## Conservation of momentum and energy

If you consider no external forces applied, ideal system, everything is conserved. If we are doing calculations you have to remember we don't care about the loses. Eg example above is what is the centrifugal force of a rotating object. Then from there we can dtermine the thing you are talking about. the required force to keep the path of the object in circle which is something needs to hold it. We assume the system is ideal. The string must be able to handle a force equal to that of the centrifugal force to be able to maintain same radius of the circle. in the case of energy. if there are no loses eg: heat friction air resistance gravity. It will continue to move on forever if no energy is transferred or transformed to other forms of energy. But we have to remember if it is a rotating body with centrifugal force acting, there is a force trying to deviate the path of the object then there are energy are loses.
8. ## Accuracy of measurements & approximates

^^^^ Yes that is the best way. When doing even basic science experiment you have to do more trials and record it. Then you get the mean. You have to consider other variables also specially if you don't have all the necessary equipments and location. Computation is whar we call theory since it may not exist in real life but proven in mathematical terms.
9. ## Is there a quick way to determine if this is a prime number?

anyways I admit I learned a lot from this thread too. Can anyone suggest good math books for advance learnings. For masterals or doctorate degree?
10. ## what are we made of?

Take note, we are a result of a reaction, it doesn't necessarily mean we are made of radiation or something, something might have reacted or fused with something thus creating something at which will combine to another something and so on and so forth. This things may not have created us but they contributed to the creation of what we are made of. Even anti matter may have contributed to that.

12. ## gabrelov

Finally passed my exams now I can focus on what I really want to read

1. Congratulations

13. ## Is there a quick way to determine if this is a prime number?

Sir Unity may I ask what happened? Hve you found out if that is a prime?
14. ## Definite Integration (Physics problem, sort of)

Nope thats not always the case, if we integrate one side with time the other doesn't necesarily with time. It maybe such state such as point 1 to 2 or what happened to the other side as we integrate it from time 1 to time 2. The above is a clear example as time passes the initial velocity becomes final velocity so you get from state 1 to state 2 of something after some time passes. In laymans term, example you have zero velocity at time zero, what would happen at velocity at time "t" offcourse in law of physics there should be a force to increase the velocity so there is acceleration.
15. ## Indefinite Integration

Transform it to something you can do trigonometric substitution You know: LIATE
16. ## [Help] Geometry Question

whats the problem with that? There are good books in math if you want to begin read Geometry for dummies McIntesh
17. ## Thermodynamics qns help!

That would be correct
18. ## If space is so cold, why is the Earth so warm?

There is something wrong in the statement, if you would face directly in the sun without atmosphere in space without suit or protection you would have burned, it could reach temperatures up to 200 degree celsius, but since space is almost empty and vast the method of heat transfer is not good. Method of heat transfer is only through radiation. So if the object is hit by radiation then only then it temperature changes. So defibitely space has no general temperature only objects on it has temperature measure. On earth meanwhile we are not vacuum and has good heat conductivity and one radiation from sun reaches us it is scaterred all over by both the surface and moving wind. You know UVs are bad for you so actually its the rays that produces heat and unable to easily escape from our atmosphere. Like in space temperature varies as which receives more radiation and which is not, you would notice it as both poles being extreme cold temperature while near ecuator directly facing the sun is really warm as the magnitude of the ray striking has no horizontal component or is straight line. Remember the basic law of thermodynamics, objects near each other will try to become in thermal equilibrium and since earth is not vacuum and is capable of conducting heat throughout then it will try to reach thermal equilibrum but due to the different heating properties of material it will do that unevenly and take time and somehow will not able to do so since the earth rotates and the process couldnt keep up.
19. ## Time travel not logical according to current laws

Even in most mathematical formula it states so there is always entrophy they say. That is for macroscopic scale.
20. ## Relative density question, finding volumes

I don't know why this is asked here, again if you can't solve this one alone it will be hard to go through all your studies, maybe you'll understand that if you know the unit of density and mass first.
21. ## Fluid Mechanics-Continuity Equation

Sorry sir I tought it was like a question that needs simple explanation and no problem solving involved
22. ## Fluid Mechanics-Continuity Equation

What is the problem with that?
23. ## How much do you love math?

Can I borrow your formula and picture to show to my friends
24. ## Is there a quick way to determine if this is a prime number?

I am very sorry sir I cannot help you yet since my exams are approaching near and I am very nervous already and really spending all my time studying. I hope you understand.
25. ## Help? Biology question..

A living thing has both genetics and cellular structure and same to nonliving things, FYI even a paper has cellular structure we call cellulose. Maybe the question will be on how their genetics and cellular structure works because almost all living things has capability to multiply simply because if it does not multiply it won't survive.
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